Which of the following combinations has the dimension of electrical resistance ($$ \in $$₀ is the permittivity of vacuum and $$\mu $$₀ is the permeability of vacuum)?

The transfer characteristic curve of a transistor, having input and output resistance 100 $$\Omega $$ and 100 k$$\Omega $$ respectively is shown in the figure. The voltage and power gain, are respectively:

When M₁ gram of ice at –10^oC (specific heat = 0.5 cal g^{–1 o}C^–1 ) is added to M₂ gram of water at 50C, finally no ice is left and the water is at 0°C. The value of latent heat of ice, in cal g^–1 is :

A man (mass = 50 kg) and his son (mass = 20 kg) are standing on a frictionless surface facing each other. The man pushes his son so that he starts moving at a speed of 0.70 ms^–1 with respect to the man. The speed of the man with respect to the surface is :